Audit of bloodborne virus infections in injecting drug users in general practice.

Two hundred and ninety patients attending a single general practice in Edinburgh were known to have used illegal drugs, 145 of whom were identified as past or present injectors. Data on bloodborne virus infections and immunisation against hepatitis B virus (HBV) were gathered during 1998, attempts were made to improve the level of testing for bloodborne viruses and immunisation against HBV, and follow up was carried out between October 1999 and February 2000. One hundred and fifteen patients were studied in detail. Evidence of previous HBV infection was found in 31 of 71 tested in 1998 (44%) and 40 of 99 tested at follow up (40%). In 1998 54 out of the 75 tested for hepatitis C antibodies (72%) were positive compared with 73 out of 108 (68%) at follow up. Twenty-six of the 80 tested for HIV antibodies were positive in 1998 (33%) and 26 of 105 at follow up (25%). Large numbers of injecting drug users in our study were found to be not immune to hepatitis B and required immunisation. An abbreviated protocol for immunisation was devised, including post vaccination checks and boosting as necessary. Hepatitis C testing was requested after counselling in most cases, resulting in important and positive interventions. Prevention opportunities for all three bloodborne viruses were identified.